WO2014188215A2

WO2014188215A2 - Thermoregulation and compression device

Info

Publication number: WO2014188215A2
Application number: PCT/GB2014/051597
Authority: WO
Inventors: Nicholas Rose
Original assignee: Physiolab Technologies Limited
Priority date: 2013-05-23
Filing date: 2014-05-23
Publication date: 2014-11-27
Also published as: WO2014188215A3

Abstract

A device for heating or cooling a body part employs open-celled foam (or a functional equivalent) in a thermal chamber to maintain the shape and structure of the chamber and ensuring that fluid flow is evenly distributed. This improves the even cooling or heating effect of the device.

Description

THERMOREGULATION AMD COMPRESSION DEVICE

Technical Field The present invention relates to a device for heating or cooling a body part for the treatment of physical injuries and disorders. Optionally, the device can also provide compression to the body part.

Background Art

It has been known for a number of years that physical injuries (for example injuries sustained during sport) can be treated by applying compression to the injury and cooling it below ambient temperatures (so-called cold pressure therapy). In simple terms, the thermal cooling tends to reduce the inflammatory response and the pain from the heat generated by the injury and the compression seems to reduce the swelling caused by fluid acumination beneath the skin.

Thermal treatments of this type have been known for many years, in their simplest form being ice packs. Subsequently, heat generating packs were developed, typically in the form of a pouch of chemical material which can be made to react exothermically and thereby to release heat. These devices are intended to cool or heat, as appropriate, a part of a person's body in order to alleviate inflammation, pain suffered by the patient and so on. It has been found that if properly applied, such treatments can significantly minimise patient discomfort caused by the injury or illness as well as speed up the recovery process.

Traditional methods of providing compression have been equally crude. In its simplest form, compression can be applied simply by the patient or the medic pushing the ice pack (for example) into the body part to be treated. A slightly more sophisticated method may involve strapping a thermal regulation pack onto the patient's limb by means of Velcro® attachments, for example. However, it has been found that the act of wrapping a flat treatment pack around a three- dimensional limb results in an uneven heating/cooling effect. In particular, when the heating or cooling is provided by the flow of a heating or cooling fluid along channels disposed in the treatment pack, the act of wrapping the pack around the limb and securing it causes uneven compression of the pack and uneven impediment of fluid flow within the channels. Thus, at worse, a situation may arise in which the limb or a part of the limb is not being cooled/heated at all, or at the very least the limb is not being heated/cooled in an even and controllable manner, thereby reducing the effectiveness of the treatment. Some prior art devices employ one of more flat packs through which the heating or cooling fluid can flow, and it may be possible to arrange these in such a manner as to minimise the compression of the packs when the device is attached to the body part. However, therapeutic compression of the body part will inevitably still result in compression of the thermal layer and consequent uneven impediment of thermal fluid flow, with all the disadvantages outlines above.

A similar problem of compression of the thermal layer is found in the present applicant's tubular therapeutic device disclosed in a PCT application filed on even date herewith and with common priority application no. GB 1309310.9.

A further disadvantage with prior art devices is that, even when not subjected to uneven compression, the flow of heating or cooling fluid through the device can be uneven, resulting in an uneven heating or cooling effect. Attempts have been made to address this problem by the provision of one or more conduits for the fluid, and by arranging the conduits to conduct the fluid evenly across the device, but this is a relatively expensive solution in manufacturing terms.

Summary of the Present Invention In accordance with a first aspect of the present invention, there is provided a device for heating or cooling a user's body part, comprising a first chamber for thermal contact with a body part, said chamber having an inlet and an outlet for a first fluid, wherein the first fluid can be heated or cooled in use to heat or cool a body part, wherein the first chamber includes a material through which the first fluid can flow in use. The preferred function of the material is (i) to protect the fluid flow from being impeded by compression or (ii) to promote even distribution of fluid or a combination of (i) and (ii).

Preferably, this material has multiple pathways (which may be equally deformable) therethrough for the first fluid which enable even distribution of the fluid through the chamber. Examples of such a material include a plurality of particles (such as polyballs), a 3D spacer material, a fluid (such as a gas or a viscous liquid) or (most preferably) an open- celled foam.

In a preferred embodiment, an open-celled foam having a porosity of from 5 to 15, more preferably about 10 pores per square inch (PPI) is employed, such as a 6mm thick reticulated polyurethane foam. The advantage of this porosity is that that the cuff does not take on too much liquid and instead creates thin randomised channels close to the tissue.

The provision of such a material has the advantages of taking up space in the first chamber (so that a smaller volume of the first fluid is required), maintaining the shape and structure of the chamber, and ensuring that fluid flow is evenly distributed. This improves the even cooling or heating effect of the device.

The first chamber may have a fluid conduit therein, in which case the material through which the fluid flows is housed within the conduit. The conduit can be configured in whichever manner is desired to (for example) maximise thermal transfer from the fluid to the body part.

In one embodiment, the device additionally comprises a second chamber having an inlet and an outlet for a second fluid, the first and second chambers being arranged so that, in use, the second fluid can be put under pressure in the second chamber in order to compress the first chamber against the body part. When the second chamber is pressurised to compress the first chamber onto the body part, there may be excess material resulting from the outer wall of the first chamber having a greater surface area that the surface area of the body part. A further technical advantage of the device is that this excess material can be accommodated in the second chamber in the form of ridges, wrinkles or rucks, without this excess material impeding the flow of fluid within the first chamber. This "ruckling" effect has the dual advantage of dynamically conforming the device to the body part and maximising the surface area of the cooling or heating effect. In another embodiment, an alternative or additional means may be provided for compressing the first fluid chamber into the body part. For example, an outer wall of electroactive material may be provided that contracts to provide compression when activated. Alternatively, a relatively inelastic outer wall may be provided such as to resist outward force resulting for example from increased pressure in the first fluid chamber and instead to direct the force inwardly to compress the fluid chamber into the body part. At its simplest, the outer wall of the first fluid chamber is more resistant or has a stronger elasticity than the inner wall of said chamber.

One advantage of the material through which the first fluid flows is that it supports fluid passages through the first chamber and prevents their being crushed/collapsed by compression caused by pressurisation of the second chamber.

Brief Description of the drawings A number of preferred embodiments of the invention will now be described, with reference to the accompanying drawings, in which:

Figure la is a schematic cross-sectional view of a device in accordance with the invention worn on a body part;

Figure lb is a schematic cross-sectional view of an alternative embodiment of a device in accordance with the invention worn on a body part; Figure 2 is an enlarged schematic cross-sectional view of a device in accordance with the invention in use;

Figure 3 is an enlarged schematic view of open-celled foam for a device in accordance with the invention, and

Figures 4a and 4b show schematic cross-sectional views of an alternative embodiment of a device in accordance with the invention.

Turning to Figure la, thermal cuff 10 is shown wrapped around a patient's arm 100.

Thermal chamber 20 is bounded by thermal chamber walls 25 and is located in use closest to arm 100 and in thermal contact therewith.

Thermal chamber 20 has an inlet and an outlet (not shown) for allowing thermal fluid to be pumped through chamber 20 to heat or cool arm 100 as required. Thermal chamber 20 is filled with open-celled foam 40 having foam structure 45 and open cells 47 as shown in close-up in Figure 3 through which the thermal fluid can flow. The open-celled nature of the foam acts to randomise the flow path of the thermal fluid, thereby resulting in even distribution of the fluid and consequent even heating or cooling of arm 100.

In an alternative embodiment, thermal chamber 20 may be filled with 3 D spacer material instead of foam, the interstices within the fibres providing the channels for thermal fluid flow.

Pressure chamber 30 is bounded by pressure chamber walls 35 and is located on and bonded to the side of thermal chamber 20 opposite to arm 100. In the embodiment shown, the outer thermal chamber wall 25 forms the inner pressure chamber wall 35. An inlet and outlet (not shown) allows pressure chamber 30 to be filled and emptied with a pressurising fluid (for example air). Pressure chamber walls 35 (particularly the outside wall) are thicker and less flexible than thermal chamber walls 25 and hence pressurising chamber 30 causes compression of thermal chamber 20 into arm 100.

In its 'unwrapped' configuration (not shown), thermal cuff 10 is generally rectangular in plan form, with a first layer which is thermal chamber 20 and a second layer which is pressure chamber 30. A Velcro® 'hook' fastening strip is disposed down one edge of the rectangle on one face and a corresponding 'eye' fastening strip is disposed down the opposite edge of the rectangle on the opposite face. Accordingly, cuff 10 can be wrapped around arm 100 and the two Velcro® strips overlapped to fasten cuff 10 around arm 100. Overlap 50 of Velcro® strips 55 is shown in Figure la.

It will be appreciated that alternative methods of securing cuff 10 around arm 100 may be provided, such as straps or belts. An alternative embodiment of a cuff 10 is accordance with the invention is shown in

Figure lb. In many respects, cuff 10 of Figure lb is similar to cuff 10 of Figure la, except that it can be seen that three thermal chambers 20 and three pressure chambers 30 are provided for wrapping circumferentially around arm 100. Thus, each thermal chamber 20 and pressure chamber 30 pair is bounded by a single outer wall 60 and divided into thermal and pressure chambers by inner wall 65. The advantage of this embodiment is that each of the three pairs of chambers can be pressurised/heated/cooled independently by means of independent fluid inlets and outlets (not shown).

In use, pressuring pressure chamber 30 causes thermal chamber 20 to compress against arm 100, thereby maximising the heating or cooling effect. As noted above, when pressure chamber 30 is pressurised to compress thermal chamber 20 onto arm 100, there may be excess material resulting from the outer wall 25 of thermal chamber 20 having a greater surface area that the surface area of arm 100. As shown in Figure 2, this excess material can be accommodated in pressure chamber 30 in the form of ruck 70, which is formed from the inner and outer wall 25 of thermal chamber 20 and foam 40 following a 'U-bend'. It can be seen that inner wall 25 of thermal chamber 20 contacts itself at point 75, and that foam 40 maintains fluid communication up to point 75 on each side.

Without wishing to be constrained by theory, it is thought that even if fluid does not flow around the U-bend in ruck 70, there is likely to be thermal transfer within the

heating/cooling fluid across point 75, and that this is facilitated by the maintenance of open fluid passageways by foam 40 within thermal chamber 20. An alternative design of thermal cuff 220 is illustrated in Figures 4a and 4b, and is described in more detail in the present applicant's PCT application filed on even date herewith and with common priority application no. GB 1309310.9 (the contents of which are incorporated herein by reference).

Tubular cuff 220 comprises a thermal chamber 222 which is defined by the cylindrical space between cylindrical inner wall 223 and cylindrical separator wall 224. Pressure chamber 226 is defined by the space between separator wall 224 and outer wall 227, such that pressure chamber 226 completely surrounds thermal chamber 222 and is concentric with it. The hollow space defined by tubular inner wall 223 is the space into which body part 221 is placed prior to treatment.

Thermal chamber 222 has fluid input and output ports (not shown) and pressure chamber 226 has air input and output ports (not shown).

It can be seen that thermal chamber 222 is filled with open-celled foam 225 (specifically, 6mm reticulated polyurethane foam with a porosity of 10 pores per inch).

A key technical advantage of this construction is that any excess material formed of inner wall 223, open-celled foam 225 and separator wall 224 is automatically accommodated by pressure chamber 226 to enable thermal chamber 222 to surround and contact body part 221 completely without flow of liquid within thermal chamber 222 being impeded. This is shown schematically in Figures 4a and 4b, in which Figure 4a shows cuff 220 under no compression and Figure 4b shows cuff 220 under compression caused by pressurised air in pressure chamber 226 compressing thermal chamber 222 against body part 221. It can be seen that thermal chamber 222 completely contacts and surrounds body part 221 and that the parts of thermal chamber 222 which are in excess are accommodated within pressure chamber 226 in the form of ruckles 240. It is preferable for the material defining thermal chamber 222 to be sufficiently thin to allow it to collapse into itself so that the excess material can move into the space of the pressure chamber 226 to form ruckle 240.

Claims

1. A device for heating or cooling a body part, comprising

a first chamber for thermal contact with a user's body part, said chamber having an inlet and an outlet for a first fluid, wherein the first fluid can be heated or cooled in use to heat or cool a body part,

wherein the first chamber includes a material through which the first fluid can flow in use.

2. A device as claimed in claim 1, wherein the material has multiple pathways therethrough for the first fluid which enable even distribution of the fluid through the chamber.

3. A device as claimed in claim 2, wherein said pathways are equally deformable.

4. A device as claimed in any of claims 1 to 3, wherein said material comprises an open-celled foam, a plurality of particles, a 3D spacer material, or a fluid.

5. A device as claimed in claim 4, wherein the open-celled foam has a porosity of from 5 to 15 pores per square inch.

6. A device as claimed in any preceding claim, wherein the first chamber has a fluid conduit therein, and wherein said material is housed in the fluid conduit.

7. A device as claimed in any preceding claim, wherein in use the device may be wrapped around the body part in order to provide thermal contact between the body part and the first chamber.

8. A device as claimed in claim 7, additionally comprising means for securing the device around the body part.

9. A device as claimed in any of claims 1 to 6, wherein the first chamber is formed by a space between an inner wall in the form of a cylindrical surface and an outer wall in the form of a cylindrical surface.

10. A device as claimed in claim 9 which is in the form of a hollow tube.

11. A device as claimed in any preceding claim, additionally comprising means for compressing the first chamber against the body part.

12. A device as claimed in claim 11, wherein said means for compressing comprises a second chamber having an inlet and an outlet for a second fluid,

the first and second chambers being arranged so that, in use, the second fluid can be put under pressure in the second chamber in order to compress the first chamber against the body part.

13. A device as claimed in claim 11 or 12, wherein said means for compressing comprises an electroactive outer wall for the first chamber, which compresses the first chamber against the body part when electroactivated.

14. A device as claimed in any of claims 11 to 13, wherein said means for compressing comprises a thicker or relatively inelastic outer wall for the first chamber, which forces the first chamber into the body part when the first chamber is pressurised.

15. A device as claimed in claim 12, wherein the second chamber does not

continuously surround the first chamber.

16. A method for providing heating or cooling and optional compression to a body part, comprising

providing a device as claimed in any preceding claim,

placing said device around a body part, and causing a first fluid to flow into the first chamber under pressure in order to cool or heat the body part.

17. A kit comprising a device as claimed in any of claims 1 to 15 and a source of hot or cold fluid.